The invention relates to an assembly of two opposing parallel guides and a panel having two opposite parallel lateral edges cooperating with said guides for a frictional sliding movement of the panel relative to the guides.
For obtaining a stable position and reproducible movement of the panel relative to the guides, a well-defined amount of friction should occur between the lateral edges and the guides. In a known assembly, the lateral edges are provided with slide shoes that are housed within the guides and cooperate therewith. It is a disadvantage of said slide shoes, however, that small dimensional variations (due to production tolerances) result in large variations of the frictional force and thus the sliding force of the panel.
It is an object of the present invention to provide an assembly as stated above, in which the influence of dimensional variations on the frictional forces is dramatically decreased.
Thus, in accordance with a first aspect of the present invention, there is provided an assembly of two opposing parallel guides and a panel having two opposite parallel lateral edges cooperating with said guides for a frictional sliding movement of the panel relative to the guides, wherein the said edges of the panel are resiliently curved or disposed in such a manner that there are defined three contact points between each edge and corresponding guide, i.e. two contact points near the ends of each edge and an intermediate contact point.
As a result of said curved edges of the panel with three distinct, spaced contact points at each edge that produce frictional forces and slide forces for the panel that do not or hardly vary with varying dimensions. But also variations in the shape of the panel (or the edges thereof) do not have a large influence on the resulting frictional forces. Thus, according to the invention, an assembly is provided in which the panel always experiences a rather consistent slide force, which will lead to reproducible results.
Although it is possible, that the two opposite parallel lateral edges of the panel themselves directly cooperate with the guides, in one embodiment of the assembly according to the invention the contact points are defined on tabs extending from the respective edges of the panel. Thus, at each respective lateral edge, three tabs are defined. In total, the panel comprises six tabs.
Said tabs can be realized in many ways. For example, the tabs can comprise extensions of or projections from the respective parallel lateral edges of the panel, attached thereto in any appropriate manner, or the tabs may be the result of the provision of recesses in the respective edges.
In still a further embodiment of the assembly according to the invention, the guides each are provided with two opposing guide surfaces positioned at a distance between them that is larger than the corresponding thickness of the tabs positioned between said opposing guide surfaces. The tabs near the ends of one edge engage the same guide surface of the guide, whereas the intermediate tab engages the other guide surface of the guide. As a result, the influence of dimensional variations on the experienced frictional forces is further minimized.
For obtaining the desired effect, only the respective edges of the panel have to be curved in one embodiment. However, it is also possible that the panel is curved in its entirety. This enables a simple manufacture of the panel.
The assembly according to the present invention can be provided in an open roof assembly for a vehicle, with a roof opening defined in the fixed roof of the vehicle and a movable closure element for opening and closing said roof opening, wherein the panel according to the present invention defines a sunshade.
In a second aspect, the present invention relates to a sunshade for application in an assembly according to the present invention.
In a third aspect, the present invention relates to a sunshade, in one embodiment, (but not necessarily) as set forth above, having a main body manufactured from a glass-reinforced composite material with a substrate layer and a foam layer and covered on one side by a cloth, wherein at least at the contact points the composite material is compressed in such a manner that the cloth ends laterally at or in the immediate vicinity of the substrate. Not only is such an embodiment of the sunshade helpful in further minimizing variations of the frictional forces due to dimensional variations, but it also reduces disturbing noises which otherwise would occur as a result of the engagement of the lateral foam layer edge with the corresponding guide.
Further, it is possible that the composite material ends laterally in a substantially sharp edge.
In one embodiment, the sunshade is manufactured from a high performance thermoplastic material, such as that made by Azdel(copyright), Inc. of Shelby, N.C.